The present invention relates to scissors and more particularly to a pair of scissors for angularly cutting a sheet stock (e.g., plastic steel, plastics, wood, etc.) with improved characteristics.
A pair of conventional scissors for angularly cutting a sheet stock (e.g., plastic steel, plastics, wood, etc.) is shown in FIG. 6. The scissors comprises a lower handle unit 11 having a U-shaped section, the lower handle unit 11 comprising aligned apertures 111 in the forward, aligned, elongated slots 112 behind the apertures 111, a block 113 disposed in the slots 112, aligned small apertures 114 below the slots 112, an elongate member 116, and a rivet 115 inserted through a rearward hole of the elongate member 116 and the apertures 114 for causing the elongate member 116 to be pivotal about the rivet 115 by manipulating a forward knob 117 of the elongate member 116; a blade 12 comprising a forward cutting edge 121, a rearward notch 123, the block 113 being disposed laterally across the slots 112 and the notch 123, an intermediate aperture 122, and a pin 124 inserted through the apertures 111 and 122; an upper handle unit 13 having a U-shaped section, the upper handle unit 13 comprising a forwardly projecting, channel-shaped arm 131, aligned apertures 132 in the forward, two openings 133 in the rear, a bolt 14 driven through the aligned openings 133, the apertures 122 and a washer 141 to be fastened by a cap nut 141, and a bottom recess 134 at the rear end of the arm 13, the recess 134 being adapted to lock the elongate member 116; an elongate, resilient piece 15 having a hole 151 in the rear fastened to the upper handle unit 13 by a rivet, the resilient piece 15 having a forward end disposed in the lower handle unit 11; a board 16 of sector-shaped comprising a lower ridge 161 disposed in the channel of the arm 131, a number of apertures 162 through the ridge 161 in which one of the apertures 162 is aligned with the apertures 132, a bolt 163 driven through washers 164, the apertures 132, and the aperture 162 to be fastened by a cap nut 165, a central slit 166, a cut 167 at the rearward end of the slit 166, the cut 167 being urged against arcuate top sides of the arm 131, and a plurality of equally spaced lines 168 originated from about the cut 167. In operation, place a sheet member formed of plastic steel, plastics, or wood on the board 16. Next, position the sheet member on the board 16 by aligning one side of the sheet member with one of the lines 168. Next, close the blade 12 on the sheet member by working the lower and upper handle units 11 and 13 against each other. Finally, the sheet member is angularly cut.
However, the prior art suffered from several disadvantages. For example, the sheet member tends to slip forward in the cutting process. This condition is particularly significant when the sheet member is relatively thick. In a case that the sheet member is formed of wood fiber the cut portion of the sheet member may squeeze toward the forward, uncut portion thereof. Hence, more force is required to cut the sheet member completely. Also, an uneven surface is formed on the cut portion of the sheet member, resulting in detraction from the sheet member""s external appearance. Hence, a need for improvement exists.
It is therefore an object of the present invention to provide a pair of scissors for angularly cutting a sheet stock comprising an upper handle unit of U-shaped, the upper handle unit comprising a forwardly projecting, channel-shaped arm, forward apertures, and intermediate apertures; a lower handle unit of U-shaped, the lower handle unit comprising a channel-shaped forward arm having forward apertures, rivet apertures in a rear of the forward apertures thereof, first apertures below the rivet apertures, and oblique slots in a rear of the first and the rivet apertures; a blade comprising a cutting edge, a first aperture, and a rearward rivet aperture; a board of sector-shaped comprising a flat top, a lower ridge having a rear projected end, an elongate slot in a rear of the ridge, and an aperture in a forward of the ridge; a pair of fasteners each having an enlarged head and a shank; and an elongate, resilient piece disposed in the upper handle unit; wherein in assembly the forward apertures of the upper handle unit is aligned with the aperture of the board after placing the ridge in the arm of the upper handle unit with the flat top supported on the arm of the upper handle unit, insert first pins through the forward apertures of the upper handle unit and the aperture of the board to cause the board to pivotal about the upper handle unit, the elongate slot is aligned with the first apertures of the lower handle unit prior to inserting a second pin through the first apertures of the lower handle unit and the elongate slot with the head of the second pin urged against the first aperture of the lower handle unit, insert a rivet through the rivet apertures of the lower handle unit and the rivet aperture of the blade for fastening, the first aperture of the blade is aligned with the forward apertures and intermediate apertures of the upper handle unit after placing the arm of the lower handle unit in the arm of the upper handle unit and placing the blade in the arm of the lower handle unit sequentially, pivotably fasten the lower and the upper handle units and the blade together by inserting third pins through the forward apertures of the lower handle unit, the intermediate apertures of the upper handle unit, and the first aperture of the blade, the shanks of the fasteners are inserted into the oblique slot to be defined therein, and the heads of the fasteners are slidably urged against the oblique slot; for closing the scissors hold the lower and the upper handle units to apply force toward each other, the lower and the upper handle units are operative to close each other by pivoting about the third pins, the board and the cutting edge close on the sheet stock to be cut on the flat top by pivoting about the first pins in response to pivoting the upper handle unit, the flat top and the blade close on each other by pivoting about the first pins in response to pivoting the lower handle unit, a rear end of the elongate slot contacts the second pin as the fasteners have slid to a lowest point in the oblique slot to be urged by the ridge so that the ridge is prevented from further rearward movement with energy stored in the resilient piece; for opening the scissors push the fasteners to a highest point in the oblique slot prior to loosening a grip on the lower and the upper handle units, the stored energy of the resilient piece is applied on the blade to expand the lower and the upper handle units away from each other, the cutting edge and the flat top pivot about the first and the third pins respectively to open an opening therebetween, a forward end of the elongate slot contacts the second pin, and form a gap between a forward end of the blade and that of the flat top; and in a cutting operation press the lower and the upper handle units against each other for causing the board and the blade to close on the sheet stock, the ridge pivots in response to pivoting the lower handle unit, the second pin slides along the elongate slot to move the ridge, a rear portion of the flat top moves upward, and a pointed end of the blade closes on a forward end of the flat top. By utilizing this, the sheet stock can be smoothly, evenly cut by the blade.
The above and other objects, features and advantages of the present invention will become apparent from the following detailed description taken with the accompanying drawings.